There is an increasing desire for electrically adjustable pieces of furniture. With many tables, in particular desks, the level of the table plate can be electrically adjusted by means of a specific drive system. Beds, for example, comfort beds or hospital beds, may also be adjusted in their height or angle of inclination through electrical drive systems.
In the electrically adjustable pieces of furniture, linear actuators are used for required linear movements, which usually comprise an AC motor or a brushed DC motor whose rotational movement is converted into the linear movement with the aid of mechanical converting means.
Brushed DC motors of this type have a large constructional height in order to be able to provide a sufficient amount of mechanical energy for the linear movement. The large constructional height, however, impedes the construction of linear actuators in compact designs.
On the other hand, an exact driving scheme which is required for linear actuators in the furnishing sector can only be achieved with large effort in the case of an AC motor. Moreover, a required AC voltage is usually not available in the furnishing sector or can only be provided with increased effort in terms of safety aspects.